This invention pertains to a system for heating or cooling a fluid, and more particularly to a fluid heating or cooling system in which the fluid is heated or cooled during fluid flow.
Various systems are known for heating or cooling a fluid during flow of the fluid through a flow path in a vessel. In particular, numerous prior patents disclose complicated serpentine flow paths in a vessel through which the fluid flows, and arrangement of heating or cooling elements within the fluid flow path. In such systems, the construction of the vessel is relatively complicated, resulting in a relatively high cost of manufacture. Further, such systems typically require that the fluid flow at a relatively low velocity in order to heat or cool the fluid to the desired temperature, resulting in a less than optimal output of heated or cooled fluid.
It is an object of the present invention to provide a vessel for heating or cooling a fluid which is simple in its construction and operation, providing a relatively low cost of manufacture. It is further object of the invention to provide such a vessel in which the heating or cooling elements are arranged to provide optimum exposure of the fluid to the heating or cooling elements, enabling the fluid to be circulated through the vessel at a relatively high velocity to increase the output of heated or cooled fluid from the vessel. Yet another object of the invention is to provide a fluid heating or cooling vessel in which the heating or cooling elements are easily removed for service or replacement.
In accordance with one aspect of the invention, an assembly for heating or cooling a fluid consists of an outer tubular shell which defines first and second ends and one or more side walls, and an inner tubular member mounted within the outer tubular shell. The inner tubular member also defines first and second ends and one or more side walls. The inner tubular member defines an internal passage forming a first flow path, and a space between the side walls of the inner tubular member and the side walls of the outer tubular shell forms a second flow path. The first and second flow paths are in communication with each other adjacent one of the ends of the inner tubular member. A first inlet/outlet opening is in communication with the first flow path and isolated from the second flow path, and a second inlet/outlet opening is in communication with the second flow path and isolated from the first flow path. A series of fluid heating or cooling elements are disposed in the first flow path, and likewise a series of second fluid heating or cooling elements are disposed in the second flow path. Fluid is introduced through one of the inlet/outlet openings and flows through the first and second flow paths, and is heated or cooled by the fluid heating or cooling elements during fluid flow. The heated or cooled fluid is then discharged through the second inlet/outlet opening.
In accordance with other aspects of the invention, the first end of the inner tubular member is spaced from the first end of the outer tubular shell, and a seal member is located toward the first end of the inner tubular member between the inner tubular member and the outer tubular shell for cutting off communication between the first and second flow paths. A first end plate is mounted to the first end of the outer tubular shell, and cooperates with the seal member and the one or more side walls of the outer tubular member to define an inlet/outlet chamber. The first inlet/outlet opening is formed in the outer tubular shell, and communicates through the inlet/outlet chamber with the first flow path. A second end plate is mounted to the second end of the outer tubular shell and is spaced from the second end of the inner tubular member. The second end plate and the one or more side walls of the outer tubular shell cooperate to define a transfer chamber in the space between the end plate and the second end of the inner tubular member, for establishing communication between the first and second flow paths. The plurality of first and second fluid heating or cooling elements are mounted to the second end plate, and extend from the second end plate into the first and second flow paths. In one form, the fluid heating or cooling elements are in the form of heater elements which extend throughout a majority of the length of the first and second flow paths.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.